Solvent fractionation of fatty materials



May 15, 1951 F. E. LACEY ETAL l 2,552,797

soLvENT FRACTIONATION oF FATTY MATERIALS Filed June 25, 1945 cH LLER NA?mh BY ffl/@ Arroz/#Ey Patented May 15, 1951 SOLVENT FRACTIONATION OFFATTY MATERIALS Felix E. Lacey and William M. Leaders, Chicago, Ill.,assignors, by mesne assignments, to Swift & Company, a corporation ofIllinois Application June 25, 1945, Serial No. 601,374

6 Claims.

This invention relates to the treatment of fatty materials to separatedesired constituents. More particularly, the invention has to do withthe solvent fractionation of fatty materials such as fats, fatty oilsand fatty acids to produce puriiied fractions of different solubility.The invention has particular application to the treatment of relativelycrude materials to produce fractions thereof improved in color and moreadapted for specific commercial uses.

Natural fatty materials often contain undesirable color bodies which arenecessary to be re moved in the manufacture of commercial products.These color bodies are intensified by normal processes of oxidativedeterioration and in many cases render the fatty material unsuited forcommercial usage. The color bodies are diii cult to remove and oftenrequire expensive factory treatment resulting in low yields. Many fattymaterials are composed of relatively high melting point and relativelylow melting point mixtures. The loW melting point material is in greaterdemand than the higher melting point material which is of limitedcommercial use as now prepared.

An object of the present invention is to provide an improved method ofremoving the color from fatty materials.

Another object of the invention is to provide a process for treatment offatty materials heretofore unavailable for the producti-on of high gradeproducts.

Another object of the invention is to remove certain impurities fromfatty materials which interfere with subsequent processing operations.

A further object of the invention is to provide an improved process oftreating fats and fatty oils whereby increased yields of desiredproducts are obtained.

A still further object of the invention is to produce from crude fattymaterials a higher melting point fraction `of enhanced value.

Also an object of the invention is to provide a more efficient processfor improving color and separating fractions of fatty materials.

The fatty materials which may be treated according to the `presentinvention comprise all grades of tallow and greases including edible andine'dible varieties, all types of vegetable and marine oils Whetherhydrogenated or unhydrogenated, and fatty acids Vderived from animal,vegetable or marine origin as well as synthetic esters and derivativesof the aforesaid fatty acids. Heretofore in the manufacture of fattyoils from greases a selection of raw material was made (Cl. Bll-4.28.5)

to provide sumciently high quality of products. The material thenrequired acid washing to remove impurities such as emulsifying agentsand crystallizing inhibitors. The product was then slowly crystallizedby gradual reduction in temperature over an extended period of time. Thecrystallized product was then separated by pressing into an oil fractionand a solid stearin fraction. The process is complicated, ineicient,`very laborious, and fails to produce suliiciently Well separatedfractions for most effective applications. The yields have beenrelatively low and the quality of the products is inferior. y f

Sperm oils have been treated heretofore in much the same manner asgreascs. The same disadvantages are in general inherent in the processof the treatment of marine oils as in the treatment of greases. In theprior methods of manufacturing fatty acids such as red oil and stearicacid raw ma-A terials Which are usually quite dark in color are oftenused. The resulting crude fatty acids are distilled to recover a lightcolor distillate and to separate the color bodies as bottoms. Thedistilled fatty acids are then subjected to repeated crystallization andpressing to separate the saturated from the unsaturated fatty acids. Insuch an operation there are high losses in the distillation step due topolymerization sometimes amounting to as much as 12%. Also the seedingor crystallizing and pressing operations are expensive, require a largeamount of equipment and require much hand labor. In the `treatment offoots resulting from the rening of vegetable oils such as cotton andsoybean oil it has been customary heretofore to acidulate and distillthe resulting released fatty acids. The losses in this operation arevery high often running to as much as 25% to 35%. 'These products havebeen suitable only for use requiring a relatively cheap source of rawmaterial.

The present invention contemplates broadlyV the treatment of the rawmaterial with a normally gaseous hydrocarbon solvent to removeundesirable color bodies under relatively high temperature and pressureconditions and the subsequent treatment of the decolorized product underlower temperature and pressure conditions to separate the product intofractions of different solubility and having different degrees ofsaturation and melting point. The process further contemplates acorrelation of the temperature and pressure conditions and a coaction ofsteps in the decolorization and solvent fractionation operations wherebyminimum refrigeration comperatures near the critical point of thehydrocari bon and under sufficient pressure to maintain the hydrocarbonin liquid phase. Infthe decolorizing operation two phases are formed,the heavier phase comprising a solution of `the color `.bodies and alighter phase comprising a Solutionfof the decolorized product. Theheavier-solution, `or foots, is separated and the propane V`recoveredleaving a dark viscous material similar to pitch. The solution ofdecolorized oil is subjected `to a depropanizing operation under areduced pressure. In the depropanizing operation the major portion ,ofthe 4propane is evaporated and the `oil chilled Vto a substantially.lower temperature. The

Y remainder of .the solution containing unvaporized propane is subjectedto additional vaporization under a further reduced pressure. In .thelatter vaporizgation operation -the oil is chilled to -a suiciently lowtemperature to crystallize the high melting point constituents,suficient propane remaining in the product to enable the mixture to bei"ltered.4 The chilled product is then filtered to remove thecrystalline portion from the solution of oiland propane. The highermelting point fraction and the .oil fraction are subjected to solvent.recovery operations to recover the propane.

The .propane rvolati'lized in the depropanizing chilling and recoveryoperations may Vbe cooled and recompressed to recover the .propane in aliquid form.

The .conditions in the decolorizing operation may vary considerably. WeAhave found that tern peratures .of 170 F. to l185 F. are satisfactoryand preferably around 175 F. The pressure should be vsuviicient tomaintain the hydrocarbon in a liquid phase at the ltemperaturespecified. Pressures within the range of 400 pounds to 530 pounds aresatisfactory, and preferably around 465 pounds per square inc-habsol-ute. 'Ihe Aratio of propane to oil in the decoloriz-ing operationmay range from between to 1 to 30 `to 1 'and preferably .about to 1 byvolume. Grdinari-ly the proportions of the two phases in thedecolorizing zone are about of the decolorized solution to 1 of theroots -although these may vary considerably depending on' thetemperature conditions. In general -it is desirable from a yield and aneciency standpoint to operate at as low a temperature as possible andyet maintain two phases.

The depropanizging operation may be Icarried out under a pressure ofabout 200 pounds to 300 pounds per square inch preferably about 250pounds per square inch, and at a temperature of 100 F. to 135 F.,preferably about 120 F. Under these conditions sufficient propane isvaporized to reduce the ratio lof propane to oil to around 4 or 5 to land preferably about 41/2 to l. 'Ihe vaporization of such quantity ofpropane would often cause undue cooling of the unvaporized solution forexample it might be sufficient to reduce the temperature to around 40 F.to 50 F. Such low temperatures are undesirable and accordingly it isadvantageous to add heat whereby the Vtempera-ture is maintained ataround 115 F. to 130 F. and preferably around 120 F. It is desirable t0.

maintain such temperature in the first stage of depropanization so thatthe further cooling and crystallization of the higher melting point fatscan be brought about subsequently under controlled conditions whichfavor the growth of more readily filtered solids. Another adyantage ofmaintaining such temperature -in the .first stage of -depropanization isthe `fact that the pressure of the Vapor formed is sufficient to permitlique- :faction by a simple condensing operation which eliminates agreat deal of mechanical compresision. 'The heat may be supplied by anysuitable means such as a direct heat exchange from a steam f orelectrical coil, or indirect heating by .an electricalheater 'or steamjacket.

In thecchilling operation the propane is slowly evaporated kby agradualreduction in the pressure, the pressure being reduced by this operationfromiabou't 250 pounds to around 30 to 75 and preferably around 50pounds. The reduction in pressure :will-cause sufficient propane to bevaporized to reduce the `ratio of propane `to-oil to .about 31/2 or 4to 1. vThe evaporation of the propane causes a reduction in temperatureof the .remaining solution to around 20 .to {40.F., preferably between0F. and +l10,F. This chilling operation must rbe controlled so that thetemperature drop is between 1 and 2 per minute, making the totalchilling time between 1 and2 hours depending upon the material beingtreated. A suitable crystal structure for good filtration is formed witha cooling speed of-about 11A" per minute, the optimum ltration Vrang'febeing fobtained with approximately a minute chilling cycle. The chilledsolution-may be filtered in .any suitable :type of pressure l'ter,`preferably a `continuous rotary filter enclosed withina vapor itypeshell. A suitable filter is one shown'in the United States patent to VanHorn No. 2,050,007.

The vinvention `will be ,more clearly understood from fthe followingdescription read `in connection with :the accompanying drawing.

Referring to the .drawing the fatty charging stock -is introduced underpressure through the line II into the upper portion of a decolorizingtower ,2. rThe tower 2 is preferably packed ywith a surface contactrmaterial rsuch as Raschig frin'gs not shown. The normally gaseous:hydrocarbon solvent is introduced into the -lower portion of the towerthrough the line The fatty material being heavier than the propanebegins to `descend through the tower counter-current tothe risingpropane solution. The temperature at the top yof the tower is preferablymaintained 2 to 10 higher than the temperature at the base of the tower.The temperature conditions maintained in the tower facilitates thecontinuous separation of color bodies from the rising propane oilsolution and enhances the efliciency of the operation from thestandpoint of oil yield. Under the temperature and pressure conditionsmaintained in the tower a separation of phases occurs. face is near thebottom, preferably below the line 3 where the propane is introduced. Theheavier phase in the lower portion of the tower is drawn off through theline 4 -controlled by a valve `5 to a depropanizer 8. A reduced pressureis maintained in the depropanizer 8 by releasing the pressure throughthe valve 5. Any propane not spontaneously evaporated by reduction inpressure may be stripped out withsteam. The depropanized oil or foots iswithdrawn from the bottom of the depropanizer through the line 9. Thepropane vapors are withdrawn from the top of the depropanizer throughthe Vaporline i0.

The inter-V al'scsave'r While one depropanizing vessel is shown it is`preferred to use three depropanizers so as to obtain a three stagedepropanization. A suitable manner of operation of the depropanizers isto use 50 pounds in the rst stage, 5 pounds in the second and steamstripping at atmospheric in the final stage. When three stages ofdepropanization are used the foots would be drawn off from the finalsteam stripping stage and the propane vapors would be withdrawn fromeach stage. The vapors from the first two stages of the depropanizationWould be pure propane whereas that from the final stage would be amixture of propane and steam. The propane may be recovered from thevapors and reused in the system.

The solution of decolorized oil and propane is withdrawn from the top ofthe decolorizer through the line l2 to a depropanizer I4. The pressurein the depropanizer I4 is maintained substantially below that in thedecolorizer 2 by operation of the reducing valve l5. The reduction inpressure will cause a vaporization of the major portion of the propaneand a reduction in temperature of the unvaporized solution. In order toavoid excessive cooling of the solution in the depropanizer heat isapplied thereto. In the drawing such heat is supplied by a steam coil I5but other means of heating may be used. The propane vapors are withdrawnfrom the top of the depropanizer through the line I8 for recovery asexplained hereinafter. The unvaporized solution is withdrawn from thelower portion of the depropanizer through the line 2D and charged to asurge tank 2|. The surge tank 2| acts merely as a reservoir for thechilling vessels 22 and 23. The solution in the surge tank may becharged alternately to Chillers 22 or 23 through the lines 24 or 25controlled by valves 26 and 2l.

In one method of operation a batch of oil is charged from the surge tankinto one of the Chillers such as vessel 22. The charge to the chiller ispreferably insufcient to completely fill the chiller so as to provide avapor space. After the vessel is charged the pressure is graduallyreleased by the valve 23 in the vapor line 30. The reduction in pressurecauses vaporization of the propane and a chilling of the oil. Whensufcient vaporization and chilling has occurred the vapor line 33 isclosed by valve 28 and the chilled oil is withdrawn from the bottom ofthe chiller through the liquid line 3| controlled by valve 32. Theliquid line communicates with a surge tank 33 whereby the oil treated inthe chiller may be withdrawn to the surge tank. The function of thesurge tank 33 is to supply a steady stream of chilled solution to therotary lter 35 which operates continuously. During the operation of thechiller 22 the chiller 23 may be charged with another batch of oil fromthe surge tank 2|. When the charge in chiller 22 is Sufliciently chilledand the valve 28 is closed the chilling operation may be commenced inthe vessel 23. This chilling operation is substantially the same as thatdescribed in connection with vessel 22 and may take place during thedischarge of the chilled yproduct from the vessel 22. Vapors fromchiller 23 are passed through vapor line 36 in which is located valve 31to vapor line 30. The chilled solution in chiller 23 is conductedthrough a liquid line 43 controlled by valve 42 to the liquid line 3|.

It will be observed that the operations of vessels 22 and 23 arealternate batch operations and are Operated in such a manner as to giveade- 6 quate time for the chilling and the formation of crystals. Thecharging and discharging times required for the loading and unloading ofvessels 22 and 23 is small in comparison to the time consumed in thechilling operations so that the two vessels operating alternatelymaintain a steady supply of chilled solution for the continuousoperation of the filter and use up sufcient warm solution from the surgetank 2|' to allow continuous operation prior to the batch chilling. Thevapors from the chillers 22 and 23 collecting in the vapor line 30 arecompressed by the -pump 45 and introduced into the vapor line I8.

The combined vapors in the line |8 are chilled in a cooler 4S to asuiciently low temperature to cause the vapors to liquefy. The liquid ispassed through the line 41 to a propane storage tank 188.

The chilled oil from the surge tank 33 is conducted through the line 50to a filter 35. The surge tank is preferably elevated somewhat above thelter 35 so that the oil feeds through the line 5U by gravity. Separationin filter 35 takes place under a positive pressure of propane gas, thesolution passing through the rotary drum. The crystalline material iscollected on the drum and subjected to a wash of cold propane to furtherreduce the liquid portion absorbed on the crystal surfaces. The crystalcake is removed from the rotary drum by a scraping mechanism whichcauses the crystalline material to fall into a trough where thetemperature is increased suiliciently to cause a solution of the crystalfat in the propane present. The solution is then conducted out of thelter through line 5| to a solvent recovery system wherein the solvent isstripped of the fat, the solvent being withdrawn through the line 53 andthe fat through the line 54. The liquid portion separated on the filteris combined with the wash solution and the mixture conducted throughline 55 to a solvent recovery system 58, wherein the solvent is strippedout and solvent as vapors passed through the vapor line 59. The oil iswithdrawn through the line 60.

As an example of the operation of the invention, a sample of browngrease was decolorized in 30 volumes of propane at a temperature ofabout 175 F. and under a pressure of about 475 pounds in a tower. Atemperature gradient of about 3 F. between the top and bottom of thetower was maintained. The lighter deoolorized liquid phase was withdrawnfrom the top of the tower and was introduced into a depropanizer with areduction in pressure to about 250 pounds. The reduction in pressurecaused suflicient propane to volatilize to reduce the propane to oilratio to about l1/2 to 1 by volume. In the latter operation additionalheat was supplied by a low pressure steam coil to maintain thetemperature of the product at about 118 F. The product was thenintroduced into a chiller wherein the pressure was gradually reduced to40 pounds per square inch over a period of about minutes. The gradualreduction in pressure was accomplished by boiling oi about 1/2 volume ofpropane producing a temperature of about 10 F. and leaving a nal ratioof propane to oil of about 4 to 1. The product was removed from thechiller, ltered, and the oil and stearin fractions stripped of theirpropane content. The yield of oil obtained in the ltrate was 81.2% andthe yield of stearin removed as press cake was 18.8%, based on thedecolorized material charged. to the lter. The yield in the decolorizingtower was 97% overhead and 3% bottoms or foots. The

-7 original .brown grease charged to the decolorizer .nadia color too.dark .to read by the F. A. C. .SYS- tem .(Fat Analysis Committee). Theoverhead from the decolorizer 'had a color of 2.9 red in a `inchLovibond column. The 3% foots obtained were .of the consistency andcolor of ordinary pitch. This pitch contained 591/2% moisture andVolatile matter, 131/2% tota] fatty acids, 1.3% nitrogen and 0.32%phosphorus, the remainder `being insoluble matter. The original browngrease had an iodine number (Wijz) of 68.0. The stearin cake from thelter had an iodine number .of 27.7, Aandthe filtrate from the filter hadan iodine number of 78.0 and a pour point o f 40 vF. The titer of thestearin was 50.1 C.

As another example of the operation of the invention, hydrolyzed whitegrease fatty acids which were too dark to read on the F. A. C. colorsystem were subjected to a propane decolorizing operation ina columnusing 30 volume propane to 1 ,of oil. The temperature was about 174 F.with a 3 F. temperature gradient and the pres- V.Sure was about 475pounds per square inch. The yield off decolorized fatty acids with acolor not darker than 1 F. A. C. was 97.3%. The bottoms or footsfraction was black and viscous and contained about total fatty acids.The decolorized overhead fraction from the tower was subjected to adepropanizing operation whereby the propane to oil ratio was reduced toabout 4 to 1 at a temperature .of .about 120 F.. and at a pressure ofabout 26.5 pounds. Heat Was supplied in the depropanizing operation byan electrical heating coil. The material was then chilled by graduallyreducing the pressure to about 45 pounds per square inch. Thetemperature was reduced to about 12 F. with an accompanying reduction ofthe propane ratio to about 3.6 to 1 of oil. The material was ltered andthe products stripped of propane. The resulting red oil fraction had aniodine number of 991/2, a titer of about '3 C. and a color not darkerthan 3 F. A. C'. The stearin or stearic acid removed from the filter hadan iodine number of 3.4 and a melting point of 124 F. The yield of redoil was 60.6% and of stearic acid was 39.4% on the basis of the overheaddecolorized product.

Soybean fatty acids obtained by the acidulation and hydrolyzing ofsoybean rening foots may be subjected to a decolorizing operation asabove described and the product subjected to a subsequent chillng andfiltration at a propane ratio of 5 to 1 and temperature of about -20 F.to 30 F. An `overhead fraction with an iodine number of about 90 and aliquid filtrate fraction with an iodine number of around 165 areobtained.

Sperm oil may be decolorized in a manner similar to that described aboveand the propane to oil ratio reduced from 20 to 1 to about 3.5 to 1 inthe depropanizing operation. A slow release of an additional 1/ volumeof propane will chill the solution from 120 F. to a temperature of 10 F.suitable for filtering. A yield of about 92.9% of sperm oil with amaximum pour point of 40 F. and 7.1% of spermaceti with an iodine numberof 15.2 and a melting point of 108 F. are obtained.

Other materials which may be treated substan* tially as described aboveinclude edible tallow, lard, cottonseed oil, coconut oil, soybean oil,sardine oil, whale oil of the glyceride variety, dark inedible tallows,yellow grease, white grease, hydrogenated fish oils, and the methylesters and fatty acids of such products. The latter materials as Well asthose mentioned .in the above examples are .included Within the meaningof the term fatty material which as used in the claims is intended tomean fats, fatty oils, and fatty acids, or mixtures thereof, and methylesters of said fats and fatty oils. The term fat as used in the claimsis intended te mean solid fats or fattir oils of animal, vegetable, ormarine origin.

While we have described the invention in connection With the use ofpropane as solvent other normally gaseous hydrocarbons such as ethane,propylene, iso and normal butanes and mixtures thereof may be used.

The present invention has the advantage of decolorizing andfractionating products in one continuous operation without the necessityof changing solvents. Also the energy required to compress the normalgaseous hydrocarbon into the liquid state for the decolorizing operationis more advantageously utilized in this process by the subsequentrefrigeration-operation in the fractionation step. For example, onaccount of the relatively high temperature conditions in thedecolorizing operation, a large amount of energy is required to maintainthe propane in the liquid phase. This excess energy is advantageouslyutilized for chilling the decolorized product and to crystaliize thehigher melting point fractions in the subsequent fractionationoperations. Moreover, in the process of the presentl invention thesolvent is more eiciently used and may be recovered with a. minimumamount of equipment and power facilities.

Obviously, many modifications and variations of the inventionhereinbefore set forth may be made Without departing from the spirit andscope thereof, and, therefore, only such limitations should be imposedas are indicated in the appended claims.

We claim:

1. A process for treating fatty materials which comprises subjecting asolution of the fatty material in a normally gaseous hydrocarbon solventto elevated temperature and pressure conditions whereby two liquidphases are formed, the lighter of said phases containing relativelylight color fatty material and the heavier of said phases containingrelatively dark color materials, separating the phases, vaporizing atleast a .portion of the normally gaseous hydrocarbon in the lighterphase by reducing the pressure While controlling the heat content of theremainder of the solution so that the temperature thereof does not fallbelow about to 135 F., chilling the solution of light color fattymaterial sufficient to precipitate a higher melting point fraction andseparating said highe1l melting point fraction from the lower meltingpoint fractions.

2. A process for refining and fractionating fatty materials whichcomprises forming a solution of the fatty material in a. normallygaseous hydrocarbon solvent, raising the temperature of the solution toaround to 185 F. to form a lighter refined liquid .phase and a heavierliquid phase containing impurities while maintaining pressuressufficiently high to retain the normally gaseous hydrocarbon in theliquid phase, separating the phases, reducing the pressure in thelighter phase sufficiently to Vaporize at least a portion of thenormally gaseous hydrocarbon thereby cooling the unvaporized portion toaround 100 to 135 F., chilling said unvaporized portion to around 20 to+40 F. to crystallize a higher melting point fraction, and separatingthe crystals from the refined product.

3. A process for refining and fractionating fats, which comprises mixingwith the fat about 20 to 30 Volumes of a liquefied normally gaseoushydrocarbon, subjecting the resulting solution. 'to temperaturessufficiently high to cause the separation of a phase containingimpurities while under pressures sufficiently high to maintain saidhydrocarbon substantially liquefied, separating said phase, vaporizing aportion of the liquefied normally gaseous hydrocarbon from the remaining solution until about 4 to 5 Volumes of hydrocarbon remain whilecontrolling the heat in said solution so that it is not chilled belowabout 100 F., continuing said chilling sufficient to cause thecrystallization of a fraction of the fat and separating saidcrystallized fraction from the re mainder of the fat.

4. A process for refining and destearinizing fats which comprisessubjecting the fatty material in the presence of liquefied propane totemperatures near the critical point of the propane whereby two liquidphases are formed, one of said phases containing decolorized fattymaterial and the other phase containing foots, separating the foots,reducing the pressure in the decolorized phase to around 200 to 300pounds thereby Vaporizing the propane and cooling the solution whilecontrolling the temperature whereby the temperature does not fall belowabout 1000 F., chilling said solution by further reducing the pressureto about 30 to 75 pounds to cause the stearin to crystallize andfiltering the solution to separate the stearin.

5. A process for refining and fractionating fatty acids which comprisesforming a solution of the fatty acids in about 15 to 30 volumes propane,subjecting said solution While under pressure sufliciently high tomaintain the propane in the liquid phase to temperatures of about 170 to185 F. at which the product separates into tWo phases, one of saidphases containing refined fatty acids and the otherl phase containingirnpurities, separating the phases, chilling the refined fatty acidphase by utilizing the heat of vaporization of the propane totemperatures sufficiently low to crystallize high melting point fattyacids, said chilling taking place in two stages, the temperature in therst stage being reduced to about 100 to 135 F.. and in the second stageto about 20 to +40 F., and filtering said crystallized fatty acids fromthe solution.

6. A process for refining and fractionating fatty materials whichcomprises subjecting a solution of the fatty material in a normallygaseous hydrocarbon solvent to temperature and pressure conditions tocause a separation of a heavier liquid phase containing impurities and alighter liquid phase containing decolorized fatty material, separatingsaid phases, reducing the pressure to Vaporize a portion of saidhydrocarbon from the lighter liquid phase while supplying heat to avoidcooling below about 100 lF., chilling the decolorized fatty material byvaporizing a further quantity of the normally gaseous hydrocarbon to atemperature suiciently low to crystallize the higher meltingconstituents of said fatty material and then filtering the mixture toseparate said higher melting point constituents.

FELIX E. LACEY. WILLIAM M.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,974,542 Parkhurst Sept. 25,1934 2,118,454 Schaafsma May 24, 1938 2,281,865 Van Dyck May 5, 19422,288,441 Ewing June 30, 1942

6. A PROCESS FOR REFINING AND FRACTIONATING FATTY MATERIALS WHICHCOMPRISES SUBJECTING A SOLUTION OF THE FATTY MATERIAL IN A NORMALLYGASEOUS HYDROCARBON SOLVENT TO TEMPERATURE AND PRESSURE CONDITIONS TOCAUSE A SEPARATION OF A HEAVIER LIQUID PHASE CONTAINING IMPURITIES AND ALIGHTER LIQUID PHASE CONTAINING DECOLORIZED FATTY MATERIAL, SEPARATINGSAID PHASES, REDUCING THE PRESSURE TO VAPORIZE A PORTION OF SAIDHYDROCARBON FROM THE LIGHTER LIQUID PHASE WHILE SUPPLYING HEAT TO AVOIDCOOLING BELOW ABOUT 100* F., CHILLING THE DECOLORIZED FATTY MATERIAL BYVAPORIZING A FURTHER QUANTITY OF THE NORMALLY GASEOUS HYDROCARBON TO ATEMPERATRE SUFFICIENTLY LOW TO CRYSTALLIZE THE HIGHER MELTINGCONSITUENTS OF SAID FATTY MATERIAL AND THEN FILTERING THE MIXTURE TOSEPARATE SAID HIGHER MELTING POINT CONSISTUENTS.